Efficacy of naltrexone on acetylcholine-induced alloknesis in atopic eczema.

Atopic eczema (AE) is a chronically pruritic inflammatory skin disease. Although the mediators and exact mechanisms eliciting and sustaining pruritus are not completely known, AE patients in clinical trials have been shown to benefit under treatment with morphine antagonists. Naltrexone (NAL) is a relatively pure morphine antagonist that blocks the effects of opioids twice as much as naloxone.

Doxepin affects acetylcholine induced cutaneous reactions in atopic eczema.

Background: Atopic eczema (AE) is a chronic inflammatory skin disease with strong itching as the prominent symptom. The pathology of itch is still in discussion, but acetylcholine (ACH) seems to be a relevant pruritogenic mediator in AE. Since efficient benefit on pruritus and excoriations has been demonstrated with tricyclic agents, we investigated how the topical treatment with doxepin (5%, Boehringer Standard, Mannheim, Germany), a tricyclic compound with anticholinergic properties, may influence ACH induced itch and cutaneous sensations (erythema, wheal, axonreflex flare).